The problem of the present invention is to provide an aforementioned tool head, an aforementioned machine and a method for machining ends of a rodlike profile material.
As regards the tool head, the stated problem is solved with a tool head having the features of claim 1.
By relief turning is meant here in particular grooves, recesses, contours, etc., running radially about the rodlike profile material in the inner and/or outer wall. These recesses, grooves, etc., can have changes along the radial circumference, thus, the grooves can have a varying width or depth along the circumference or a profile differing in a cross section along the lengthwise direction. Relief-turned features can be made in any place at a distance from the end face of the profile material, for which materials is ablated from the respective material wall on the inside or outside, but without removing profile material between the end face and the ablated region. In particular, radially encircling grooves can be made in the inner and/or outer wall of the material at the particular distance from the end face of the material.
For this, the tool head of the invention has a housing, in which at least one thrusting wedge is provided, which is arranged so as to move back and forth in the longitudinal direction in a first toothed guide. The first toothed guide has two tooth profiles corresponding to each other and sliding back and forth in each other in the longitudinal direction. A first tooth profile is placed on an outer wall of the thrusting wedge, while a corresponding first tooth profile is provided on an inner wall of the respective thrusting wedge guide in a housing. The toothed guide creates an enlarged contact surface between thrusting wedge and housing; thus, a substantially improved guide as compared to a smooth t-guide or a dovetail guide, with substantially enhanced quality and better accuracy of repetition and precision.
Each of the thrusting wedges is coordinated with a support in the housing, able to move in a second toothed guide in a direction arranged transversely to the longitudinal direction. The same applies accordingly to the second toothed guide as was said about the first toothed guide of the thrusting wedge. The second tooth profile placed on the outer wall of the support interacts with a corresponding second tooth profile arranged on the inner wall of a thrusting wedge guide that is countersunk in the housing. Thanks to the enlarged contact surface, here as well one has a toothed guide of high quality. The thrusting wedge and the coordinated support are in sliding contact with each other via a slanted contact surface and a movement of the thrusting wedge in the longitudinal direction is transformed via the slanted contact surface into a transverse movement of the coordinated support. The slanted contact surface is preferably configured smooth over its entire extent and with constant gradient.
To further enhance the guiding accuracy and quality of the second toothed guide, the support has a support arm extending in the transverse direction. Preferably, the transverse direction runs perpendicularly to the longitudinal direction and in the radial direction of the cutting tool.
A cutting tool can be fastened on the support, preferably to a fastening plate. Advantageously, the cutting tool fastened to the support can thus move in the radial direction.
During operation, the tool head is in rapid rotational movement about the lengthwise axis. The tool head of the invention makes it possible to radially guide and adjust the cutting tools even during the rotational motion. For this, the tool head is mounted on a rotary transmission leadthrough, having three push rods arranged alongside each other in the longitudinal direction. The ends of the push rods can touch the thrusting wedges and enter into an active engagement with them. Preferably, a thrust force is transmitted by the push rods to the coordinated thrusting wedge.
Preferably, the at least one thrusting wedge and the at least one support are each coordinated with a return spring. The thrusting wedge can be pressed into the tool head at one end face of the tool head by thrust force on a thrusting wedge arm sticking out from the tool head in the lengthwise direction, while the same thrusting wedge is restored automatically by the return spring in the lengthwise direction.
Due to the slanted contact surface, the lengthwise movement of the thrusting wedge is diverted into a transverse movement of the support. By the pressing of the thrusting wedge, the support is moved radially inward, while when the thrusting wedge is relaxed it is moved radially outward due to its coordinated return spring. By controlled thrust force on the thrusting wedge arm, a correspondingly controlled transverse movement of the respective cutting tool is possible.
The cutting tool makes it possible, for example, to make radial relief turning features on an outer wall of a rodlike profile material that is circular in cross section. For this, the cutting tools are first moved radially outward, the tool head is placed in rotating motion, and the moved in the lengthwise direction toward the end face, far enough so that the cutting tools come up behind the end of the rodlike profile material. Only now is the cutting head moved inward under control by deliberate pressing force on the at least one thrusting wedge arm, thereby producing a relief turning in the outer wall at a distance from the end face of the profile material.
In an especially preferred embodiment of the invention, a plurality of supports is provided in the shape of a star in a cross section perpendicular to the lengthwise direction and each support has a support arm coordinated with it, running transversely. The support arms are arranged in crossing manner, looking at them in the lengthwise direction. This embodiment of the invention makes it possible to accommodate a plurality, preferably precisely three supports in the tool head in space-saving fashion, but still with high precision of guidance. Due to the crossing arrangement of the support arms, which are preferably also provided along their outer surface with a corresponding second tooth profile along their transverse direction of movement, the support still preserves a high quality of guidance and precision of replication.
Favorably, the housing is fashioned essentially in circular shape in a cross section perpendicular to the lengthwise direction, and the at least one thrusting wedge has a first outer tooth profile on opposite, radially-extending outer walls on the thrusting wedge, interacting as the first tooth guide with a first inner tooth profile on an inner wall of the thrusting wedge guide.
Advantageously, the radial outer walls of a thrusting wedge which is rectangular in cross section perpendicular to the lengthwise direction are provided precisely with a first outer tooth profile extending in the lengthwise direction. The corresponding first inner tooth profile is placed on the inner wall of the thrusting wedge guide in the housing.
All tooth profiles are produced in especially precise manner by wire-EDM. Wire-EDM makes it necessary for the tooth profiles to extend over the entire dimension of the corresponding guides of the structural part.
In another preferred embodiment of the invention, the at least one support has a second outer tooth profile on opposite, radially-extending walls, interacting with a second inner tooth profile on an inner wall of the support guide for the second toothed guide. The second toothed guide is preferably led radially through the housing, perpendicular to the lengthwise direction. The other second tooth profile favorably extends over the entire radial dimension of the support arm. Due to the additional second toothed guide of the support, an especially high accuracy and quality of guidance is achieved.
Preferably, the at least one thrusting wedge has a constant design height. By design height is meant here the dimension of the thrusting wedge perpendicular to the lengthwise direction and perpendicular to the radius of the tool head. For cost savings, the thrusting wedges are identical in construction.
In another preferred embodiment of the invention, the part of the at least one support provided in the housing also has a constant design height along its entire dimension.
Advantageously, the thrusting wedge projects into the support guide temporarily during the operation. For this, the design height of the thrusting wedge is less than the design height of the support by the tooth depth of the second tooth profile.
Support and thrusting wedge in one economical embodiment of the invention are automatically reset by appropriately dimensioned return springs.
Regarding the machine for machining of the ends of a rodlike profile material, the stated problem is solved by a machine with a tool head as described above. A machine which enables a corresponding control of the tool head has, for example, a rotary transmission leadthrough.
Regarding the method, the problem is solved by a method for machining the ends of a rodlike profile material, in that a radial relief turning is produced in one wall of the profile material. Such a method can be implemented by a tool head as described above and a machine as described above.
Preferably, the at least one support for the machining of an outer wall of the profile material is at first moved radially outward or that for the machining of an inner wall of the profile material is at first moved radially inward. In this way, it is possible to lead up the cutting tool in the lengthwise direction of the profile material behind one end surface of the profile material without contacting it, then to rotate the cutting tool relative to the profile material about a lengthwise axis oriented in the longitudinal direction and to move the cutting tool radially toward the wall during the rotation until the wall is contacted by the cutting tool, and to make a relief turning in the wall by the contacting.